BIOLOGY AND SOCIOLOGY 101 



to touch upon. But for one thing I have not the 

 time, and for another, Mr. Carr-Saunders in his re- 

 cent book on the Population Problem has dealt so 

 fully with the relation between biological inheritance 

 and what may be called tradition-inheritance, that I 

 omit them with a good conscience. 



In this brief treatment I have had to ask you to 

 take conclusions on trust, without presenting the 

 evidence on which they are based; this, however, 

 is inevitable when transferring ideas from one science 

 to another. I have attempted to show, first, that 

 biology can profit by incorporating certain conclu- 

 sions of sociology and so rounding off and complet- 

 ing certain of its own principles: on the other hand, I 

 have put before you my belief that there are certain 

 basic biological principles which must be taken into 

 account by the sociologist — principles which hold 

 good in sociology because man too is an organism. 



By now, however, we can see more clearly the way 

 in which the various sciences with which we are con- 

 cerned, of whose relations we had something to say 

 at the beginning of this essay, properly interlock. 



They interlock thus. The physico-chemical sci- 

 ences are basic to biology. Organisms are made of 

 the same substances as are non-living compounds; 

 their processes are therefore conformable to certain 

 physico-chemical laws, such as the indestructibility 

 of matter, the conservation of energy, and so forth; 

 and in so far as we analyse the material aspect of life, 

 physico-chemical concepts are adequate. On the 



